Heat exchangers are used in various industries to heat or cool various types of liquids and gases.
Most small heat exchangers are designed using a pipe or tube shell with individually fabricated baffles, tie rods, tube sheets and tubes; turbulators are sometimes used inside of the tubes to improve heat transfer.
A shell and tube heat exchanger is comprised of two sections, each of which conveys a separate fluid placed in the particular section that offers the most advantageous heat transfer for that fluid. Of these sections; one is known as the shell side and the second is known as the tube side. The two sections must accommodate conditions such as access for servicing, different pressures and may require different materials of construction in order to comply with corrosion and strength requirements.
This invention relates to heat exchangers, and in particular, to a heat exchanger having baffles and tube supports which are integral with its shell.
In order to clarify the difference between baffles and turbulators; baffles are used outside of the tubes in a manner to create turbulence and improve heat transfer by controlled flow. Turbulators or deflectors, are generally used inside of tubes to break up laminar flow.
The construction of heat exchangers thus requires securing many parts together. In a small heat exchanger, this can be difficult because of the small diameter that is being worked on. Further, the construction of the heat exchanger requires the stocking of numerous parts.
U.S. Pat. Nos. 2,677,394 to Brinen, et al., and No. 2,688,986, to O'Biren disclose turbulators formed from a sheet for use in the tubes of a heat exchanger. However, I do not know of anyone who has designed heat exchanger wherein the shell, baffles, and the tube sheets are integrally formed.
More specifically with respect to the prior art patents known to applicant, the patent to Muffly, No. 1,709,865, discloses the process of forming refrigerator elements, and the pertinency of this particular patent is to show that various components for equipment, such as the refrigeration plates, can be formed from shaped metal that is stamped and adhere together, as to be noted in FIGS. 2 and 3 of the particular device.
The patent to Lambert, No. 1,996,622, merely shows extended surface method of attachment of components of a metal radiator together. This discloses a sheet form of metal radiator. This device, once again, as can be seen, appears to be formed from a plurality of sheets of material, wherein a series of vertically disposed fins are attached to the halves of the sheet metal radiator, in order to provide the heat exchange fins, for the heating system as disclosed.
The patent to Brinen, as referred to above, No. 2,677,394, shows turbulators for installation inside of tubes. In this particular patent, as can be seen, there is contained internal structure of a spine section of a heat exchanger, which incorporates a series of sections or lobes, which are struck out, partially as to be seen, from the spine component which then integrally has a pair of lateral flanges to provide for their connection interiorly of the tube. This particular patent does not show how the entire tube section can be integrally formed from the spine component itself, after the spine has had its various lobes stamped and bent into their disclosed configuration.
Also, the patent to O'Brien, as previously referred to, No. 2,688,986, once again shows turbulators inside of tubes. This discloses a similar type of what is identified as a turbulence member, which has a variety of tongues stamped from it, and bent perpendicularly, to form the baffling configuration for the heat exchanger, as when the turbulence member is inserted within its respective tube, as can be noted.
The patent to Guala, No. 2,693,942, shows a respectable baffle design. However, this particular design is formed from multiple pieces. It discloses a further heat transfer apparatus. In this particular embodiment, the baffles appear to be formed from a single circular sheet, and then cut, stamped, and bent, into their perpendicularity, before their insertion within their respective enclosing shell of a heat exchanger. As is well known, the baffles, with their arranged openings are designed for holding the tubes of the heat exchanger.
The patent to Man Suk Lee, No. 3,400,758, shows another formed from multiple pieces. It discloses another form of helical baffle means in a tubular heat exchanger. As can be seen, this particular device shows the method for forming baffles, having a variety of bends or other shaped configurations, particularly as can be seen in the patent drawings, with these baffles then being secured into position within the heat exchanger's shell, as can be noted.
The patent to Friedman, No. 3,739,443, discloses how to construct together a shell with tight fitting baffles. This particular configuration for a heat exchanger has been around for approximately forty years. This patent discloses a method of forming a shell and tube heat exchanger. This particular patent shows a series of bundles of tubes, as can be noted in its disclosure, having supporting sheets at either end, and then the half shells are folded therearound, and clamped into position by means of the clamping strips.
The patent to Parker, No. 3,769,959, is an enlarged version of what previously was shown in the Brinen, O'Brien, and Neveux patents, for constructing turbulence inside of a tube. The tube in this particular instance may be larger and is odd shaped, but it is not integrally formed. The patent further discloses a type of heating tube and baffle arrangement for deep fat fryers. As can be noted, the baffling arrangement includes the baffle means with an outer tube arranged therearound. But it does not appear that this particular structure integrally.
The patent to Neveux, No. 4,106,558, shows another turbulator, in this particular instance, it is identified as a deflector for use inside of tubes. The patent discloses another form of a deflector for a heat exchanger tube. But, once again, while the deflectors may be formed as a series of stampings, as can be seen in its drawings, once these deflectors are fabricated, they are then split into their separate tubes for locating within a heat exchanger. It appears that the shaped cylindrical sections are independently formed, before any baffle is arranged therein.
The patent to Melnyk, et al, No. 4,546,825, describes a conventional heater, differing in that the shell of this heater is corrugated and the baffles are held in place by the recess in the corrugations. The patent specifically discloses a heat exchanger and method of assembly thereof. This particular embodiment appears to be very similar to the configuration of the previously described Freidman heat exchanger, wherein the baffles are formed independently, to support their tube bundle, but that the outer shell is formed of a pair of half angular shells.
The patent to Duncan, No. 4,727,907, discloses another form of a turbulator, with integral flow deflector tabs, which are configured as a stamping, apparently for locating within the heat exchanger pipe.
The patent to Yeh, No. 4,832,114, describes a scraped heat exchanger, and shows a device for producing high heat transfer in the heat exchanger tubes, with the internal baffling arrangement, as to be seen, being independently formed, and then apparently supported for rotation therein, by means of bearing mounts. There may even be sweeping elements provided upon the periphery of the shown strip.
These prior patents show and describe the use of a turbulator for application inside of a heat exchanger tube, especially small tubes. These types of devices were designed for use as oil coolers for diesel engines, and the like, even though they may have other applications. Other designs in the prior art as disclosed above attempt to minimize leaks between the baffles and the shell within the heat exchanger, or they are other variations upon the tube type turbulators. None of the designs in the prior art disclose a shell and baffle assembly, fabricated from a single metal plate material, into an integral type of unit.